This invention pertains to the field of ground fault circuit interrupter devices, and in particular, to a ground fault interrupter device with an indicator lamp powered from the hot bus bar of the interrupting contacts of the device.
Protective devices such as ground fault circuit interrupters (GFCIs) are well known in the art. Their intent is and always has been to protect the electrical power user from electrocution when hazardous ground fault currents are present.
Historical problems with these protective devices include the possibility of line/load miswiring in the field by an installer or the eventual failure of the solenoid driving device, typically a silicon controlled rectifier, which causes the interrupter device to become inoperable while electrical power is still present, even under hazardous ground fault conditions. A variety of methods are used to prevent or attempt to prevent miswiring with varying levels of success. Preventing the problems associated with a defective solenoid driving device is inherently more difficult. Labels and installation instruction sheets have been used to prevent miswiring, but can be ignored by the installer. Solenoid burn-out has been revealed by testing the protective device with a test button, but the result of the test can be ignored by the user.
Briefly stated, an AC power line protection device which includes miswiring protection has an indicator lamp which lights when the device is in the tripped condition and turns off when the device is reset. If the device is miswired after having been wired properly, the indicator lamp does not light when the device is tripped, and so provides a supplemental indication of miswiring. The indicator lamp is powered via the hot line bus bar of the interrupting contacts to meet safety standards.
According to an embodiment of the invention, a protection device connected between hot and neutral conductors of an AC power line includes a protective circuit including a breaker coil operatively associated with a set of interrupting contacts, wherein the interrupting contacts include a hot bus bar; and an indicator lamp circuit including an indicator lamp connected between the hot conductor on a line side of the interrupting contacts and the hot bus bar.
According to an embodiment of the invention, a protection device connected between hot and neutral conductors of an AC power line includes protective means for protecting a load side of the AC power line against a ground fault; the protective means including a breaker coil operatively associated with a set of interrupting contacts, wherein the interrupting contacts include a hot bus bar; indicator means for indicating a specified condition of the protection device; and the indicator means being connected between the hot conductor on a line side of the interrupting contacts and the hot bus bar.
According to an embodiment of the invention, a method for protecting against miswiring a protection device connected between hot and neutral conductors of an AC power line, wherein the device includes an interrupter having two contacts on a hot bus bar connected respectively to line hot and load hot terminals and two contacts on a neutral bus bar connected respectively to line neutral and load neutral terminals, wherein the interrupter opens and closes to electrically disconnect and connect the load terminals, respectively, includes the steps of (a) operatively associating a breaker coil of a protective circuit with the interrupter; and (b) connecting an indicator lamp circuit between the hot conductor on a line side of the interrupter and the hot bus bar.
According to an embodiment of the invention, a method for protecting against miswiring a protection device includes the steps of (a) protecting a load side of the AC power line against a ground fault via the protection device; (b) operatively associating a breaker coil with a set of interrupting contacts inside the protection device, wherein the interrupting contacts include a hot bus bar; (c) indicating a specified condition of the protection device with an indicator; and (d) connecting the indicator between the hot conductor on a line side of the interrupting contacts and the hot bus bar.